1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
1
00:00:00,180 --> 00:00:03,090
As another example, I want to show you the architecture of the
2
00:00:03,090 --> 00:00:06,290
iRods system. This is a data grid system that was built by
3
00:00:06,290 --> 00:00:09,720
a biologist. And it's a system for storing and accessing big
4
00:00:09,720 --> 00:00:11,910
data. So what I'm going to do, I'm going to do the same thing
5
00:00:11,910 --> 00:00:14,010
that I did for the Linux system. I'm going to show you
6
00:00:14,010 --> 00:00:18,080
here, on the left hand side, this clean prescriptive architecture for the
7
00:00:18,080 --> 00:00:21,000
iRODS system. And I'm going to show you here on the right the
8
00:00:21,000 --> 00:00:22,660
actual architecture of the system. The
9
00:00:22,660 --> 00:00:25,780
descriptive architecture of iRODS. So here,
10
00:00:25,780 --> 00:00:27,640
even if we don't go in and look at the details, you
11
00:00:27,640 --> 00:00:31,800
can see very easily that the system is badly drifted and eroded
12
00:00:31,800 --> 00:00:34,500
with respect to the way it was supposed to be. Continuing
13
00:00:34,500 --> 00:00:36,500
with the examples. What I want to show you now is the
14
00:00:36,500 --> 00:00:39,980
view of the complete architecture of HADOOP. As many of you probably
15
00:00:39,980 --> 00:00:44,210
already know, HADOOP is an open source software framework for storage and
16
00:00:44,210 --> 00:00:47,990
large scale processing of data sets. It's very broadly used. And here
17
00:00:47,990 --> 00:00:50,820
is a picture of the architecture, and I hope you can see it
18
00:00:50,820 --> 00:00:54,290
because the architecture is so complex and so broad and so
19
00:00:54,290 --> 00:00:57,050
intertwined, and in order to be able to represent it here
20
00:00:57,050 --> 00:00:59,690
in one page, I had to zoom out quite a bit.
21
00:00:59,690 --> 00:01:02,120
But also in this case, you don't really have to look
22
00:01:02,120 --> 00:01:05,640
at details. The important point here is that in this software architecture
23
00:01:05,640 --> 00:01:09,540
61 out of the 67 components in the system have circular
24
00:01:09,540 --> 00:01:12,570
dependencies. Which means that they depend on each other in a
25
00:01:12,570 --> 00:01:15,820
circular way and this is normally not a good thing and also
26
00:01:15,820 --> 00:01:18,790
in this case a few developers when shown the diagram had no
27
00:01:18,790 --> 00:01:22,120
idea that the structure of the system was so complex and messy.
|
